It was previously thought that only Prince William, Prince Harry and three royal aides had voicemails illegally intercepted. But other members of the Royal Family, as well as their family and friends, were also targeted – possibly including the Middletons – according to the U.K.'s Sunday Telegraph.

"It was much more widespread than was known at the time, and it involved a lot more people and a lot more hacking at all levels," a source tells the paper. The palace had no comment.

Rogue journalists at the since-shuttered News of the World "reached out and targeted as many people as they could in that world," the source says. "If they've targeted Prince William and Prince Harry, you can assume that they targeted their friends and immediate family."

Earlier this summer it was alleged that a private investigator who once worked for the News of the World hacked Middleton's bank records in 2005. That her phone may have been hacked is a new charge, and one that falls under an investigation code-named Operation Weeting.